The Neurovirology (NV) Core has the overall objective to support, through national and international collaboration and capacity-building, efforts at the genotypic identification and phenotypic characterization of HIV that is associated with neuroAIDS. Our scientific and service aims are to (1) identify the genotype of neuroadaptive HIV at varying stages of HIV-associated neurological disease; (2) to determine the phenotype of this neuroadaptive genotype; and (3) to develop methods for investigating viral dynamics and evolution within the CNS, especially in the setting of co-occurring conditions like other viral co-infections, bacterial translocation and HIV dual infection. Since viral populations in the CNS can be genetically distinct from populations in other tissues, such as blood, lymphoid and genital tract, appropriate virologic techniques will be needed to characterize neurotropism and neurovirulence in the CNS. The NV Core will enhance the HNRC's transdiciplinary aims through close collaboration with the Neurobehavioral, Neuromedical and Neurobiology Cores, utilizing multiple virologic techniques specific to CNS derived virus and its analysis. Considerable amounts of virologic data, specifically sequence data, will be generated through the research supported by this Core, including international collaborations. Management of these data will be aided through web-based systems, developed in cooperation with the Data Management and Information Systems Unit. Investigating the impact of HIV-associated neurological disease throughout the world will require the development of location-specific virologic capabilities and remote-access to analytical methods that have been validated for use in neuroAIDS investigations: these will be supported by the NV Core. Through existing (e.g., Brazil, India, Romania and China) and planned (e.g., Mexico, Ethiopia, and South Africa) collaborations, we will provide technical support in the development of molecular virology capabilities to address the specific research objectives of each locale. The NV Core, with its variety of cutting-edge molecular virologic techniques, is essential to fundamental advances in understanding the neuropathogenesis of HIV.